1. Field of the Invention
The present invention relates to a safety system for vehicles and, more particularly, to a motorized seatbelt retractor capable of retracting a seat belt by a motor.
2. Description of the Related Art
An automatic motorized seatbelt retractor capable of automatically retracting a seat belt is one of protective devices for protecting the passengers of a vehicle in the case of an accident. The automatic motorized seatbelt retractor applies a strong tension to the seat belt to retract the seat belt instantly when a collision is detected. To retract the seat belt by a high pulling force, the set belt retractor uses an explosive, a spring or a motor.
Whereas a motorized seatbelt retractor using an explosive can execute a set belt retracting operation only once, a motorized seatbelt retractor using a motor for retracting a seat belt can repeat a seat belt retracting operation any number of times. To make the best use of the distinctive feature of the motorized seatbelt retractor, trials have been made to apply the motorized seatbelt retractor to other purposes other than retracting the seat belt when collision occurs. A motorized seatbelt retractor disclosed in JP-A 2001-114069 retracts a seat belt for warning when collision is predicted.